A 0.6-mW 16-FSK Receiver Achieving a Sensitivity of −103 dBm at 100 kb/s

Abstract

This article presents an RF receiver (RX) designed to exploit the inherent SNR advantage offered by non-coherent 16-FSK modulation relative to more conventional non-coherent modulation schemes, such as FSK and OOK. Specifically, this article demonstrates that when demodulated using two-pole bandpass filters, 16-FSK offers a 4-dB sensitivity advantage compared with binary frequency shift keying (BFSK), at the cost of reduced spectral efficiency at the same data rate. This article then presents the design of a 16-FSK-compatible RX front end, which performs demodulation through 16 N-path filters driven by temperature-stabilized phase-locked loops to ensure calibration-free filter center frequency control, along with augmented Miller capacitors for tight area-constrained bandwidth control. Implemented in 65-nm CMOS, the RX consumes 0.6 mW from a 0.5-V supply while achieving a sensitivity of -103.2 dBm at 100 kb/s, for a power-sensitivity-data-rate figure of merit of 185.2 dB, which represents a 3.2 dB advance over state of the art.